diff --git a/mesonbuild/modules/cmake.py b/mesonbuild/modules/cmake.py
index ee40b442d757..a178b2373228 100644
--- a/mesonbuild/modules/cmake.py
+++ b/mesonbuild/modules/cmake.py
@@ -267,7 +267,7 @@ def detect_voidp_size(self, env):
         if not compiler:
             raise mesonlib.MesonException('Requires a C or C++ compiler to compute sizeof(void *).')
 
-        return compiler.sizeof('void *', '', env)
+        return compiler.sizeof('void *', '', env)[0]
 
     def detect_cmake(self, state):
         if self.cmake_detected: