diff --git a/cpp/ql/lib/semmle/code/cpp/Function.qll b/cpp/ql/lib/semmle/code/cpp/Function.qll
index 10b156e3fb64..b5ea5b3cbc73 100644
--- a/cpp/ql/lib/semmle/code/cpp/Function.qll
+++ b/cpp/ql/lib/semmle/code/cpp/Function.qll
@@ -524,6 +524,14 @@ class Function extends Declaration, ControlFlowNode, AccessHolder, @function {
       not exists(NewOrNewArrayExpr new | e = new.getAllocatorCall().getArgument(0))
     )
   }
+
+  /**
+   * Holds if this function has ambiguous return type (this occurs sometimes in
+   * Build Mode None).
+   */
+  predicate hasAmbiguousReturnType() {
+    count(this.getType()) != 1
+  }
 }
 
 pragma[noinline]
diff --git a/cpp/ql/src/Likely Bugs/Arithmetic/IntMultToLong.ql b/cpp/ql/src/Likely Bugs/Arithmetic/IntMultToLong.ql
index a54ac9020c8c..6747d177c80e 100644
--- a/cpp/ql/src/Likely Bugs/Arithmetic/IntMultToLong.ql	
+++ b/cpp/ql/src/Likely Bugs/Arithmetic/IntMultToLong.ql	
@@ -218,7 +218,9 @@ where
   // only report if we cannot prove that the result of the
   // multiplication will be less (resp. greater) than the
   // maximum (resp. minimum) number we can compute.
-  overflows(me, t1)
+  overflows(me, t1) and
+  // exclude cases where the expression type may not have been extracted accurately
+  not me.getParent().(Call).getTarget().hasAmbiguousReturnType()
 select me,
   "Multiplication result may overflow '" + me.getType().toString() + "' before it is converted to '"
     + me.getFullyConverted().getType().toString() + "'."
diff --git a/cpp/ql/src/change-notes/2026-03-11-integer-multiplication-cast-to-long.md b/cpp/ql/src/change-notes/2026-03-11-integer-multiplication-cast-to-long.md
new file mode 100644
index 000000000000..a0efd8a87852
--- /dev/null
+++ b/cpp/ql/src/change-notes/2026-03-11-integer-multiplication-cast-to-long.md
@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* Fixed an issue with the "Multiplication result converted to larger type" (`cpp/integer-multiplication-cast-to-long`) query causing false positive results in Build Mode Node databases.
diff --git a/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/Buildless.c b/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/Buildless.c
new file mode 100644
index 000000000000..3d01a28fae0a
--- /dev/null
+++ b/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/Buildless.c	
@@ -0,0 +1,28 @@
+// semmle-extractor-options: --expect_errors
+
+void test_float_double1(float f, double d) {
+    float r1 = f * f; // GOOD
+    float r2 = f * d; // GOOD
+    double r3 = f * f; // BAD
+    double r4 = f * d; // GOOD
+
+    float f1 = fabsf(f * f); // GOOD
+    float f2 = fabsf(f * d); // GOOD
+    double f3 = fabs(f * f); // BAD [NOT DETECTED]
+    double f4 = fabs(f * d); // GOOD
+}
+
+double fabs(double f);
+float fabsf(float f);
+
+void test_float_double2(float f, double d) {
+    float r1 = f * f; // GOOD
+    float r2 = f * d; // GOOD
+    double r3 = f * f; // BAD
+    double r4 = f * d; // GOOD
+
+    float f1 = fabsf(f * f); // GOOD
+    float f2 = fabsf(f * d); // GOOD
+    double f3 = fabs(f * f); // BAD [NOT DETECTED]
+    double f4 = fabs(f * d); // GOOD
+}
diff --git a/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.expected b/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.expected
index 2806aaa809fe..05b2b7e1ea3c 100644
--- a/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.expected	
+++ b/cpp/ql/test/query-tests/Likely Bugs/Arithmetic/IntMultToLong/IntMultToLong.expected	
@@ -1,3 +1,5 @@
+| Buildless.c:6:17:6:21 | ... * ... | Multiplication result may overflow 'float' before it is converted to 'double'. |
+| Buildless.c:21:17:21:21 | ... * ... | Multiplication result may overflow 'float' before it is converted to 'double'. |
 | IntMultToLong.c:4:10:4:14 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'long long'. |
 | IntMultToLong.c:7:16:7:20 | ... * ... | Multiplication result may overflow 'int' before it is converted to 'long long'. |
 | IntMultToLong.c:18:19:18:23 | ... * ... | Multiplication result may overflow 'float' before it is converted to 'double'. |