diff --git a/cpp/ql/src/Likely Bugs/Underspecified Functions/MistypedFunctionArguments.qll b/cpp/ql/src/Likely Bugs/Underspecified Functions/MistypedFunctionArguments.qll
index 2dced5d8d84..dbb457db505 100644
--- a/cpp/ql/src/Likely Bugs/Underspecified Functions/MistypedFunctionArguments.qll	
+++ b/cpp/ql/src/Likely Bugs/Underspecified Functions/MistypedFunctionArguments.qll	
@@ -79,9 +79,7 @@ private predicate hasZeroParamDecl(Function f) {
 
 // True if this file (or header) was compiled as a C file
 private predicate isCompiledAsC(File f) {
-  f.compiledAsC()
-  or
-  exists(File src | isCompiledAsC(src) | src.getAnIncludedFile() = f)
+  exists(File src | src.compiledAsC() | src.getAnIncludedFile*() = f)
 }
 
 predicate mistypedFunctionArguments(FunctionCall fc, Function f, Parameter p) {
diff --git a/cpp/ql/src/Likely Bugs/Underspecified Functions/TooFewArguments.qll b/cpp/ql/src/Likely Bugs/Underspecified Functions/TooFewArguments.qll
index 218a54b36c5..fd323513a49 100644
--- a/cpp/ql/src/Likely Bugs/Underspecified Functions/TooFewArguments.qll	
+++ b/cpp/ql/src/Likely Bugs/Underspecified Functions/TooFewArguments.qll	
@@ -28,9 +28,7 @@ private predicate hasZeroParamDecl(Function f) {
 
 /* Holds if this file (or header) was compiled as a C file. */
 private predicate isCompiledAsC(File f) {
-  f.compiledAsC()
-  or
-  exists(File src | isCompiledAsC(src) | src.getAnIncludedFile() = f)
+  exists(File src | src.compiledAsC() | src.getAnIncludedFile*() = f)
 }
 
 /** Holds if `fc` is a call to `f` with too few arguments. */
diff --git a/cpp/ql/src/Likely Bugs/Underspecified Functions/TooManyArguments.qll b/cpp/ql/src/Likely Bugs/Underspecified Functions/TooManyArguments.qll
index 7fba78b5550..ab2a98ae3a5 100644
--- a/cpp/ql/src/Likely Bugs/Underspecified Functions/TooManyArguments.qll	
+++ b/cpp/ql/src/Likely Bugs/Underspecified Functions/TooManyArguments.qll	
@@ -19,9 +19,7 @@ private predicate hasZeroParamDecl(Function f) {
 
 // True if this file (or header) was compiled as a C file
 private predicate isCompiledAsC(File f) {
-  f.compiledAsC()
-  or
-  exists(File src | isCompiledAsC(src) | src.getAnIncludedFile() = f)
+  exists(File src | src.compiledAsC() | src.getAnIncludedFile*() = f)
 }
 
 predicate tooManyArguments(FunctionCall fc, Function f) {