Index: src/OFMutableArray.m
==================================================================
--- src/OFMutableArray.m
+++ src/OFMutableArray.m
@@ -117,10 +117,22 @@
 
 			[array removeItemAtIndex: i];
 			mutations++;
 
 			[obj release];
+
+			/*
+			 * We need to get the C array again as it might have
+			 * been relocated. We also need to adjust the count
+			 * as otherwise we would have an out of bounds access.
+			 * As another object will be at the current index now,
+			 * we also need to handle the same index again, thus we
+			 * decrease it.
+			 */
+			objs = [array cArray];
+			count--;
+			i--;
 		}
 	}
 
 	return self;
 }
@@ -134,10 +146,22 @@
 		if (objs[i] == obj) {
 			[array removeItemAtIndex: i];
 			mutations++;
 
 			[obj release];
+
+			/*
+			 * We need to get the C array again as it might have
+			 * been relocated. We also need to adjust the count
+			 * as otherwise we would have an out of bounds access.
+			 * As another object will be at the current index now,
+			 * we also need to handle the same index again, thus we
+			 * decrease it.
+			 */
+			objs = [array cArray];
+			count--;
+			i--;
 		}
 	}
 
 	return self;
 }