diff --git a/cpp/ql/src/Likely Bugs/Underspecified Functions/MistypedFunctionArguments.ql b/cpp/ql/src/Likely Bugs/Underspecified Functions/MistypedFunctionArguments.ql
index 1142cc1a45b..e137e90c716 100644
--- a/cpp/ql/src/Likely Bugs/Underspecified Functions/MistypedFunctionArguments.ql	
+++ b/cpp/ql/src/Likely Bugs/Underspecified Functions/MistypedFunctionArguments.ql	
@@ -84,10 +84,10 @@ predicate hasZeroParamDecl(Function f) {
 }
 
 // True if this file (or header) was compiled as a C file
-predicate isCompiledAsC(Function f) {
-  exists(File file | file.compiledAsC() |
-    file = f.getFile() or file.getAnIncludedFile+() = f.getFile()
-  )
+predicate isCompiledAsC(File f) {
+  f.compiledAsC()
+  or
+  exists(File src | isCompiledAsC(src) | src.getAnIncludedFile() = f)
 }
 
 from FunctionCall fc, Function f, Parameter p
@@ -95,7 +95,7 @@ where
   f = fc.getTarget() and
   p = f.getAParameter() and
   hasZeroParamDecl(f) and
-  isCompiledAsC(f) and
+  isCompiledAsC(f.getFile()) and
   not f.isVarargs() and
   not f instanceof BuiltInFunction and
   p.getIndex() < fc.getNumberOfArguments() and
diff --git a/cpp/ql/src/Likely Bugs/Underspecified Functions/TooFewArguments.ql b/cpp/ql/src/Likely Bugs/Underspecified Functions/TooFewArguments.ql
index a3e78fe61c4..705c1ec4dc8 100644
--- a/cpp/ql/src/Likely Bugs/Underspecified Functions/TooFewArguments.ql	
+++ b/cpp/ql/src/Likely Bugs/Underspecified Functions/TooFewArguments.ql	
@@ -24,10 +24,10 @@ predicate hasZeroParamDecl(Function f) {
 }
 
 // True if this file (or header) was compiled as a C file
-predicate isCompiledAsC(Function f) {
-  exists(File file | file.compiledAsC() |
-    file = f.getFile() or file.getAnIncludedFile+() = f.getFile()
-  )
+predicate isCompiledAsC(File f) {
+  f.compiledAsC()
+  or
+  exists(File src | isCompiledAsC(src) | src.getAnIncludedFile() = f)
 }
 
 from FunctionCall fc, Function f
@@ -36,7 +36,7 @@ where
   not f.isVarargs() and
   not f instanceof BuiltInFunction and
   hasZeroParamDecl(f) and
-  isCompiledAsC(f) and
+  isCompiledAsC(f.getFile()) and
   // There is an explicit declaration of the function whose parameter count is larger
   // than the number of call arguments
   exists(FunctionDeclarationEntry fde | fde = f.getADeclarationEntry() |
diff --git a/cpp/ql/src/Likely Bugs/Underspecified Functions/TooManyArguments.ql b/cpp/ql/src/Likely Bugs/Underspecified Functions/TooManyArguments.ql
index b0bd7746c15..59368236bbd 100644
--- a/cpp/ql/src/Likely Bugs/Underspecified Functions/TooManyArguments.ql	
+++ b/cpp/ql/src/Likely Bugs/Underspecified Functions/TooManyArguments.ql	
@@ -25,10 +25,10 @@ predicate hasZeroParamDecl(Function f) {
 }
 
 // True if this file (or header) was compiled as a C file
-predicate isCompiledAsC(Function f) {
-  exists(File file | file.compiledAsC() |
-    file = f.getFile() or file.getAnIncludedFile+() = f.getFile()
-  )
+predicate isCompiledAsC(File f) {
+  f.compiledAsC()
+  or
+  exists(File src | isCompiledAsC(src) | src.getAnIncludedFile() = f)
 }
 
 from FunctionCall fc, Function f
@@ -36,7 +36,7 @@ where
   f = fc.getTarget() and
   not f.isVarargs() and
   hasZeroParamDecl(f) and
-  isCompiledAsC(f) and
+  isCompiledAsC(f.getFile()) and
   exists(f.getBlock()) and
   // There must not exist a declaration with the number of parameters
   // at least as large as the number of call arguments