Index: src/OFZIPArchive.m
==================================================================
--- src/OFZIPArchive.m
+++ src/OFZIPArchive.m
@@ -31,10 +31,11 @@
 #import "OFInvalidFormatException.h"
 #import "OFNotImplementedException.h"
 #import "OFOpenFileFailedException.h"
 #import "OFOutOfRangeException.h"
 #import "OFReadFailedException.h"
+#import "OFSeekFailedException.h"
 #import "OFUnsupportedVersionException.h"
 
 #import "autorelease.h"
 #import "macros.h"
 
@@ -219,12 +220,19 @@
 	uint16_t commentLength;
 	off_t offset = -22;
 	bool valid = false;
 
 	do {
-		[_file seekToOffset: offset
-			     whence: SEEK_END];
+		@try {
+			[_file seekToOffset: offset
+				     whence: SEEK_END];
+		} @catch (OFSeekFailedException *e) {
+			if ([e errNo] == EINVAL)
+				@throw [OFInvalidFormatException exception];
+
+			@throw e;
+		}
 
 		if ([_file readLittleEndianInt32] == 0x06054B50) {
 			valid = true;
 			break;
 		}

Index: utils/Makefile
==================================================================
--- utils/Makefile
+++ utils/Makefile
@@ -28,9 +28,9 @@
 				${DELETE_FAILED}; \
 			fi \
 		fi \
 	done
 
-CPPFLAGS += -I../src -I../src/runtime -I..
+CPPFLAGS += -I../src -I../src/runtime -I../src/exceptions -I..
 LIBS := -L../src -lobjfw ${LIBS}
 LD = ${OBJC}
 LDFLAGS += ${LDFLAGS_RPATH}