diff --git a/internal/planner/planner.go b/internal/planner/planner.go
index de39dc357d..fcd420ff51 100644
--- a/internal/planner/planner.go
+++ b/internal/planner/planner.go
@@ -678,7 +678,7 @@ func (p *Planner) planExprCall(e *ast.Expr, iter planiter) error {
 
 		if len(operands) == arity {
 			// rule: f(x) = x { ... }
-			// call: f(x) == 1 or f(x) # result not captured
+			// call: f(x) # result not captured
 			return p.planCallArgs(operands, 0, args, func(args []ir.Local) error {
 				p.ltarget = p.newLocal()
 				p.appendStmt(&ir.CallStmt{
@@ -686,6 +686,19 @@ func (p *Planner) planExprCall(e *ast.Expr, iter planiter) error {
 					Args:   args,
 					Result: p.ltarget,
 				})
+
+				falsy := p.newLocal()
+
+				p.appendStmt(&ir.MakeBooleanStmt{
+					Value:  false,
+					Target: falsy,
+				})
+
+				p.appendStmt(&ir.NotEqualStmt{
+					A: p.ltarget,
+					B: falsy,
+				})
+
 				return iter()
 			})
 		} else if len(operands) == arity+1 {
diff --git a/test/wasm/assets/008_functions.yaml b/test/wasm/assets/008_functions.yaml
index 3d63232f36..cffd63746a 100644
--- a/test/wasm/assets/008_functions.yaml
+++ b/test/wasm/assets/008_functions.yaml
@@ -103,4 +103,20 @@ cases:
         package x
         f(x) = 1
         f(x) = 2
-    want_error: var assignment conflict
\ No newline at end of file
+    want_error: var assignment conflict
+  - note: 'false result'
+    query: data.test.p = x
+    modules:
+      - |
+        package test
+        f(x) = false
+        p = true { f(1) }
+    want_defined: false
+  - note: 'negated false result'
+    query: data.test.p = x
+    modules:
+      - |
+        package test
+        f(x) = false
+        p = true { not f(1) }
+    want_defined: true
\ No newline at end of file