diff --git a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImpl.qll b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImpl.qll
index 28541a3837b..fb24a1db69f 100644
--- a/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImpl.qll
+++ b/cpp/ql/lib/semmle/code/cpp/ir/dataflow/internal/SsaImpl.qll
@@ -940,6 +940,11 @@ module SsaCached {
     SsaImpl::phiHasInputFromBlock(phi, inp, bb)
   }
 
+  cached
+  predicate uncertainWriteDefinitionInput(Definition uncertain, Definition inp) {
+    SsaImpl::uncertainWriteDefinitionInput(uncertain, inp)
+  }
+
   cached
   predicate ssaDefReachesEndOfBlock(IRBlock bb, Definition def) {
     SsaImpl::ssaDefReachesEndOfBlock(bb, def, _)
@@ -1178,7 +1183,7 @@ class Definition extends SsaImpl::Definition {
   private Definition getAPhiInputOrPriorDefinition() {
     result = this.(PhiNode).getAnInput()
     or
-    SsaImpl::uncertainWriteDefinitionInput(this, result)
+    uncertainWriteDefinitionInput(this, result)
   }
 
   /**