diff --git a/src/lib.rs b/src/lib.rs
index cc289d3..dc7025c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -196,6 +196,8 @@ mod tests {
 
             assert_eq!(b"RIFF", &out[0..4]);
             assert_eq!(b"WEBP", &out[8..12]);
+
+            WebPFree(out_buf as *mut _);
         }
     }
 
@@ -215,6 +217,8 @@ mod tests {
 
             assert_eq!(b"RIFF", &out[0..4]);
             assert_eq!(b"WEBP", &out[8..12]);
+
+            WebPFree(out_buf as *mut _);
         }
     }
 
@@ -259,6 +263,8 @@ mod tests {
 
             assert_eq!(b"RIFF", &out[0..4]);
             assert_eq!(b"WEBP", &out[8..12]);
+
+            WebPPictureFree(&mut picture);
         }
     }
 
@@ -285,6 +291,9 @@ mod tests {
 
             assert_eq!(b"RIFF", &out[0..4]);
             assert_eq!(b"WEBP", &out[8..12]);
+
+            WebPFree(decode_buf as *mut _);
+            WebPFree(out_buf as *mut _);
         }
     }