diff --git a/cpp/ql/src/Likely Bugs/Underspecified Functions/ImplicitFunctionDeclaration.ql b/cpp/ql/src/Likely Bugs/Underspecified Functions/ImplicitFunctionDeclaration.ql
index 6a55557cf70b..007ef71a1630 100644
--- a/cpp/ql/src/Likely Bugs/Underspecified Functions/ImplicitFunctionDeclaration.ql	
+++ b/cpp/ql/src/Likely Bugs/Underspecified Functions/ImplicitFunctionDeclaration.ql	
@@ -17,6 +17,11 @@ import TooFewArguments
 import TooManyArguments
 import semmle.code.cpp.commons.Exclusions
 
+/*
+ * This query is not compatible with build mode: none databases, and has
+ * no results on those databases.
+ */
+
 predicate locInfo(Locatable e, File file, int line, int col) {
   e.getFile() = file and
   e.getLocation().getStartLine() = line and
@@ -39,6 +44,7 @@ predicate isCompiledAsC(File f) {
 from FunctionDeclarationEntry fdeIm, FunctionCall fc
 where
   isCompiledAsC(fdeIm.getFile()) and
+  not any(Compilation c).buildModeNone() and
   not isFromMacroDefinition(fc) and
   fdeIm.isImplicit() and
   sameLocation(fdeIm, fc) and
diff --git a/cpp/ql/src/change-notes/2026-03-23-implicit-function-declaration.md b/cpp/ql/src/change-notes/2026-03-23-implicit-function-declaration.md
new file mode 100644
index 000000000000..8c2c431ec24c
--- /dev/null
+++ b/cpp/ql/src/change-notes/2026-03-23-implicit-function-declaration.md
@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* The "Implicit function declaration" (`cpp/implicit-function-declaration`) query no longer produces results on `build mode: none` databases. These results were found to be very noisy and fundamentally imprecise in this mode.