diff --git a/Lib/fontTools/otlLib/builder.py b/Lib/fontTools/otlLib/builder.py
index e3f335514..cec1ec317 100644
--- a/Lib/fontTools/otlLib/builder.py
+++ b/Lib/fontTools/otlLib/builder.py
@@ -367,9 +367,15 @@ class ChainContextualBuilder(LookupBuilder):
             contextual positioning lookup.
         """
         subtables = []
-        chaining = False
+
         rulesets = self.rulesets()
         chaining = any(ruleset.hasPrefixOrSuffix for ruleset in rulesets)
+        # Unfortunately, as of 2022-03-07, Apple's CoreText renderer does not
+        # correctly process GPOS7 lookups, so for now we force contextual
+        # positioning lookups to be chaining (GPOS8).
+        if self.subtable_type == "Pos":  # horrible separation of concerns breach
+            chaining = True
+
         for ruleset in rulesets:
             # Determine format strategy. We try to build formats 1, 2 and 3
             # subtables and then work out which is best. candidates list holds
diff --git a/Tests/feaLib/data/spec6h_ii.ttx b/Tests/feaLib/data/spec6h_ii.ttx
index 2f0efc6f2..e8ec85f28 100644
--- a/Tests/feaLib/data/spec6h_ii.ttx
+++ b/Tests/feaLib/data/spec6h_ii.ttx
@@ -112,23 +112,25 @@
         </MarkBasePos>
       </Lookup>
       <Lookup index="2">
-        <LookupType value="7"/>
+        <LookupType value="8"/>
         <LookupFlag value="0"/>
         <!-- SubTableCount=1 -->
-        <ContextPos index="0" Format="3">
-          <!-- GlyphCount=3 -->
-          <!-- PosCount=2 -->
-          <Coverage index="0">
+        <ChainContextPos index="0" Format="3">
+          <!-- BacktrackGlyphCount=0 -->
+          <!-- InputGlyphCount=3 -->
+          <InputCoverage index="0">
             <Glyph value="T"/>
-          </Coverage>
-          <Coverage index="1">
+          </InputCoverage>
+          <InputCoverage index="1">
             <Glyph value="c"/>
             <Glyph value="o"/>
-          </Coverage>
-          <Coverage index="2">
+          </InputCoverage>
+          <InputCoverage index="2">
             <Glyph value="grave"/>
             <Glyph value="acute"/>
-          </Coverage>
+          </InputCoverage>
+          <!-- LookAheadGlyphCount=0 -->
+          <!-- PosCount=2 -->
           <PosLookupRecord index="0">
             <SequenceIndex value="0"/>
             <LookupListIndex value="0"/>
@@ -137,7 +139,7 @@
             <SequenceIndex value="2"/>
             <LookupListIndex value="1"/>
           </PosLookupRecord>
-        </ContextPos>
+        </ChainContextPos>
       </Lookup>
     </LookupList>
   </GPOS>
diff --git a/Tests/feaLib/data/spec6h_iii_3d.ttx b/Tests/feaLib/data/spec6h_iii_3d.ttx
index 2335dd0b4..a608f0e62 100644
--- a/Tests/feaLib/data/spec6h_iii_3d.ttx
+++ b/Tests/feaLib/data/spec6h_iii_3d.ttx
@@ -30,23 +30,25 @@
     <LookupList>
       <!-- LookupCount=2 -->
       <Lookup index="0">
-        <LookupType value="7"/>
+        <LookupType value="8"/>
         <LookupFlag value="0"/>
         <!-- SubTableCount=1 -->
-        <ContextPos index="0" Format="3">
-          <!-- GlyphCount=2 -->
-          <!-- PosCount=1 -->
-          <Coverage index="0">
+        <ChainContextPos index="0" Format="3">
+          <!-- BacktrackGlyphCount=0 -->
+          <!-- InputGlyphCount=2 -->
+          <InputCoverage index="0">
             <Glyph value="L"/>
-          </Coverage>
-          <Coverage index="1">
+          </InputCoverage>
+          <InputCoverage index="1">
             <Glyph value="quoteright"/>
-          </Coverage>
+          </InputCoverage>
+          <!-- LookAheadGlyphCount=0 -->
+          <!-- PosCount=1 -->
           <PosLookupRecord index="0">
             <SequenceIndex value="1"/>
             <LookupListIndex value="1"/>
           </PosLookupRecord>
-        </ContextPos>
+        </ChainContextPos>
       </Lookup>
       <Lookup index="1">
         <LookupType value="1"/>
diff --git a/Tests/varLib/data/test_results/InterpolateLayoutGPOS_7_diff.ttx b/Tests/varLib/data/test_results/InterpolateLayoutGPOS_8_diff.ttx
similarity index 87%
rename from Tests/varLib/data/test_results/InterpolateLayoutGPOS_7_diff.ttx
rename to Tests/varLib/data/test_results/InterpolateLayoutGPOS_8_diff.ttx
index 14e120979..0086ddc3c 100644
--- a/Tests/varLib/data/test_results/InterpolateLayoutGPOS_7_diff.ttx
+++ b/Tests/varLib/data/test_results/InterpolateLayoutGPOS_8_diff.ttx
@@ -83,21 +83,23 @@
         </MarkBasePos>
       </Lookup>
       <Lookup index="2">
-        <LookupType value="7"/>
+        <LookupType value="8"/>
         <LookupFlag value="0"/>
         <!-- SubTableCount=1 -->
-        <ContextPos index="0" Format="1">
+        <ChainContextPos index="0" Format="1">
           <Coverage>
             <Glyph value="A"/>
           </Coverage>
-          <!-- PosRuleSetCount=1 -->
-          <PosRuleSet index="0">
-            <!-- PosRuleCount=1 -->
-            <PosRule index="0">
-              <!-- GlyphCount=3 -->
-              <!-- PosCount=2 -->
+          <!-- ChainPosRuleSetCount=1 -->
+          <ChainPosRuleSet index="0">
+            <!-- ChainPosRuleCount=1 -->
+            <ChainPosRule index="0">
+              <!-- BacktrackGlyphCount=0 -->
+              <!-- InputGlyphCount=3 -->
               <Input index="0" value="a"/>
               <Input index="1" value="uni0303"/>
+              <!-- LookAheadGlyphCount=0 -->
+              <!-- PosCount=2 -->
               <PosLookupRecord index="0">
                 <SequenceIndex value="0"/>
                 <LookupListIndex value="0"/>
@@ -106,9 +108,9 @@
                 <SequenceIndex value="2"/>
                 <LookupListIndex value="1"/>
               </PosLookupRecord>
-            </PosRule>
-          </PosRuleSet>
-        </ContextPos>
+            </ChainPosRule>
+          </ChainPosRuleSet>
+        </ChainContextPos>
       </Lookup>
     </LookupList>
   </GPOS>
diff --git a/Tests/varLib/data/test_results/InterpolateLayoutGPOS_7_same.ttx b/Tests/varLib/data/test_results/InterpolateLayoutGPOS_8_same.ttx
similarity index 87%
rename from Tests/varLib/data/test_results/InterpolateLayoutGPOS_7_same.ttx
rename to Tests/varLib/data/test_results/InterpolateLayoutGPOS_8_same.ttx
index eff24fc30..a32c94d03 100644
--- a/Tests/varLib/data/test_results/InterpolateLayoutGPOS_7_same.ttx
+++ b/Tests/varLib/data/test_results/InterpolateLayoutGPOS_8_same.ttx
@@ -83,21 +83,23 @@
         </MarkBasePos>
       </Lookup>
       <Lookup index="2">
-        <LookupType value="7"/>
+        <LookupType value="8"/>
         <LookupFlag value="0"/>
         <!-- SubTableCount=1 -->
-        <ContextPos index="0" Format="1">
+        <ChainContextPos index="0" Format="1">
           <Coverage>
             <Glyph value="A"/>
           </Coverage>
-          <!-- PosRuleSetCount=1 -->
-          <PosRuleSet index="0">
-            <!-- PosRuleCount=1 -->
-            <PosRule index="0">
-              <!-- GlyphCount=3 -->
-              <!-- PosCount=2 -->
+          <!-- ChainPosRuleSetCount=1 -->
+          <ChainPosRuleSet index="0">
+            <!-- ChainPosRuleCount=1 -->
+            <ChainPosRule index="0">
+              <!-- BacktrackGlyphCount=0 -->
+              <!-- InputGlyphCount=3 -->
               <Input index="0" value="a"/>
               <Input index="1" value="uni0303"/>
+              <!-- LookAheadGlyphCount=0 -->
+              <!-- PosCount=2 -->
               <PosLookupRecord index="0">
                 <SequenceIndex value="0"/>
                 <LookupListIndex value="0"/>
@@ -106,9 +108,9 @@
                 <SequenceIndex value="2"/>
                 <LookupListIndex value="1"/>
               </PosLookupRecord>
-            </PosRule>
-          </PosRuleSet>
-        </ContextPos>
+            </ChainPosRule>
+          </ChainPosRuleSet>
+        </ChainContextPos>
       </Lookup>
     </LookupList>
   </GPOS>
diff --git a/Tests/varLib/interpolate_layout_test.py b/Tests/varLib/interpolate_layout_test.py
index 18dc3a752..219f087ff 100644
--- a/Tests/varLib/interpolate_layout_test.py
+++ b/Tests/varLib/interpolate_layout_test.py
@@ -746,8 +746,8 @@ class InterpolateLayoutTest(unittest.TestCase):
         self.check_ttx_dump(instfont, expected_ttx_path, tables, suffix)
 
 
-    def test_varlib_interpolate_layout_GPOS_only_LookupType_7_same_val_ttf(self):
-        """Only GPOS; LookupType 7; same values in all masters.
+    def test_varlib_interpolate_layout_GPOS_only_LookupType_8_same_val_ttf(self):
+        """Only GPOS; LookupType 8; same values in all masters.
         """
         suffix = '.ttf'
         ds_path = self.get_test_input('InterpolateLayout.designspace')
@@ -779,13 +779,13 @@ class InterpolateLayoutTest(unittest.TestCase):
         instfont = interpolate_layout(ds_path, {'weight': 500}, finder)
 
         tables = ['GPOS']
-        expected_ttx_path = self.get_test_output('InterpolateLayoutGPOS_7_same.ttx')
+        expected_ttx_path = self.get_test_output('InterpolateLayoutGPOS_8_same.ttx')
         self.expect_ttx(instfont, expected_ttx_path, tables)
         self.check_ttx_dump(instfont, expected_ttx_path, tables, suffix)
 
 
-    def test_varlib_interpolate_layout_GPOS_only_LookupType_7_diff_val_ttf(self):
-        """Only GPOS; LookupType 7; different values in each master.
+    def test_varlib_interpolate_layout_GPOS_only_LookupType_8_diff_val_ttf(self):
+        """Only GPOS; LookupType 8; different values in each master.
         """
         suffix = '.ttf'
         ds_path = self.get_test_input('InterpolateLayout.designspace')
@@ -831,7 +831,7 @@ class InterpolateLayoutTest(unittest.TestCase):
         instfont = interpolate_layout(ds_path, {'weight': 500}, finder)
 
         tables = ['GPOS']
-        expected_ttx_path = self.get_test_output('InterpolateLayoutGPOS_7_diff.ttx')
+        expected_ttx_path = self.get_test_output('InterpolateLayoutGPOS_8_diff.ttx')
         self.expect_ttx(instfont, expected_ttx_path, tables)
         self.check_ttx_dump(instfont, expected_ttx_path, tables, suffix)