diff --git a/src/c/funktionen.h b/src/c/funktionen.h
index 6f517c5..767df58 100644
--- a/src/c/funktionen.h
+++ b/src/c/funktionen.h
@@ -7,4 +7,7 @@ float square(float x);
 // Function to calculate the square root of a number
 float squareRoot(float x);
 
+// Function to calculate the cube of a number
+float cube(float x);
+
 #endif
\ No newline at end of file