Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -39,42 +39,12 @@
 		AC_DEFINE(LLONG_MAX, 0x7FFFFFFFFFFFFFFFLL,
 			[Maximum value for long long])
 		AC_DEFINE(LLONG_MIN, [(-0x7FFFFFFFFFFFFFFFLL - 1)],
 			[Minimum value for long long])
 
-		AC_DEFINE(PRId8, "hhd", [Format string for 8-bit as decimal])
-		AC_DEFINE(PRId16, "hd", [Format string for 16-bit as decimal])
-		AC_DEFINE(PRId32, "d", [Format string for 32-bit as decimal])
-		AC_DEFINE(PRId64, "lld", [Format string for 64-bit as decimal])
-		AC_DEFINE(PRIi8, "hhi", [Format string for 8-bit as integer])
-		AC_DEFINE(PRIi16, "hi", [Format string for 16-bit as integer])
-		AC_DEFINE(PRIi32, "i", [Format string for 32-bit as integer])
-		AC_DEFINE(PRIi64, "lli", [Format string for 64-bit as integer])
-		AC_DEFINE(PRIo8, "hho", [Format string for 8-bit as octal])
-		AC_DEFINE(PRIo16, "ho", [Format string for 16-bit as octal])
-		AC_DEFINE(PRIo32, "o", [Format string for 32-bit as octal])
-		AC_DEFINE(PRIo64, "llo", [Format string for 64-bit as octal])
-		AC_DEFINE(PRIu8, "hhu", [Format string for 8-bit as unsigned])
-		AC_DEFINE(PRIu16, "hu", [Format string for 16-bit as unsigned])
-		AC_DEFINE(PRIu32, "u", [Format string for 32-bit as unsigned])
-		AC_DEFINE(PRIu64, "llu", [Format string for 64-bit as unsigned])
-		AC_DEFINE(PRIx8, "hhx",
-			[Format string for 8-bit as lowercase hex])
-		AC_DEFINE(PRIx16, "hx",
-			[Format string for 16-bit as lowercase hex])
-		AC_DEFINE(PRIx32, "x",
-			[Format string for 32-bit as lowercase hex])
-		AC_DEFINE(PRIx64, "llx",
-			[Format string for 64-bit as lowercase hex])
-		AC_DEFINE(PRIX8, "hhX",
-			[Format string for 8-bit as uppercase hex])
-		AC_DEFINE(PRIX16, "hX",
-			[Format string for 16-bit as uppercase hex])
-		AC_DEFINE(PRIX32, "X",
-			[Format string for 32-bit as uppercase hex])
-		AC_DEFINE(PRIX64, "llX",
-			[Format string for 64-bit as uppercase hex])
+		AC_DEFINE(__have_longlong64, 1,
+			[Required for AmigaOS to correctly define PRI?64])
 
 		AC_SUBST(NOIXEMUL, -noixemul)
 		;;
 	powerpc-*-amigaos*)
 		enable_shared="no"

Index: src/OFString.m
==================================================================
--- src/OFString.m
+++ src/OFString.m
@@ -2504,11 +2504,11 @@
 
 - (float)floatValue
 {
 	void *pool = objc_autoreleasePoolPush();
 
-#ifdef OF_MORPHOS
+#if defined(OF_AMIGAOS3) || defined(OF_MORPHOS)
 	OFString *stripped = [self stringByDeletingEnclosingWhitespaces];
 
 	if ([stripped caseInsensitiveCompare: @"INF"] == OF_ORDERED_SAME ||
 	    [stripped caseInsensitiveCompare: @"INFINITY"] == OF_ORDERED_SAME)
 		return INFINITY;
@@ -2554,11 +2554,11 @@
 
 - (double)doubleValue
 {
 	void *pool = objc_autoreleasePoolPush();
 
-#ifdef OF_MORPHOS
+#if defined(OF_AMIGAOS3) || defined(OF_MORPHOS)
 	OFString *stripped = [self stringByDeletingEnclosingWhitespaces];
 
 	if ([stripped caseInsensitiveCompare: @"INF"] == OF_ORDERED_SAME ||
 	    [stripped caseInsensitiveCompare: @"INFINITY"] == OF_ORDERED_SAME)
 		return INFINITY;

Index: src/OFSystemInfo.m
==================================================================
--- src/OFSystemInfo.m
+++ src/OFSystemInfo.m
@@ -111,10 +111,12 @@
 	operatingSystemName = @"macOS";
 #elif defined(OF_WINDOWS)
 	operatingSystemName = @"Windows";
 #elif defined(OF_ANDROID)
 	operatingSystemName = @"Android";
+#elif defined(OF_AMIGAOS3)
+	operatingSystemName = @"AmigaOS";
 #elif defined(OF_MORPHOS)
 	operatingSystemName = @"MorphOS";
 #elif defined(OF_AMIGAOS4)
 	operatingSystemName = @"AmigaOS 4";
 #elif defined(OF_WII)

Index: src/objfw-defs.h.in
==================================================================
--- src/objfw-defs.h.in
+++ src/objfw-defs.h.in
@@ -39,32 +39,9 @@
 #undef OF_HAVE__THREAD_LOCAL
 #undef OF_HAVE___THREAD
 #undef OF_NINTENDO_DS
 #undef OF_OBJFW_RUNTIME
 #undef OF_UNIVERSAL
-#undef PRId8
-#undef PRId16
-#undef PRId32
-#undef PRId64
-#undef PRIi8
-#undef PRIi16
-#undef PRIi32
-#undef PRIi64
-#undef PRIo8
-#undef PRIo16
-#undef PRIo32
-#undef PRIo64
-#undef PRIu8
-#undef PRIu16
-#undef PRIu32
-#undef PRIu64
-#undef PRIx8
-#undef PRIx16
-#undef PRIx32
-#undef PRIx64
-#undef PRIX8
-#undef PRIX16
-#undef PRIX32
-#undef PRIX64
 #undef SIZE_MAX
 #undef UINTPTR_MAX
 #undef ULLONG_MAX
+#undef __have_longlong64

Index: tests/OFStringTests.m
==================================================================
--- tests/OFStringTests.m
+++ tests/OFStringTests.m
@@ -876,24 +876,28 @@
 	 * These test numbers can be generated without rounding if we have IEEE
 	 * floating point numbers, thus we can use == on them.
 	 */
 	TEST(@"-[floatValue]",
 	    [C(@"\t-0.25 ") floatValue] == -0.25 &&
-	    [C(@"\r\n\tINF\t\n") doubleValue] == INFINITY &&
+	    [C(@"\r\n\tINF\t\n") floatValue] == INFINITY &&
 	    [C(@"\r -INFINITY\n") floatValue] == -INFINITY &&
 	    isnan([C(@"   NAN\t\t") floatValue]))
 
-#if !defined(OF_ANDROID) && !defined(OF_SOLARIS) && !defined(OF_DJGPP)
+#if !defined(OF_ANDROID) && !defined(OF_SOLARIS) && !defined(OF_DJGPP) && \
+    !defined(OF_AMIGAOS3)
 # define INPUT @"\t-0x1.FFFFFFFFFFFFFP-1020 "
 # define EXPECTED -0x1.FFFFFFFFFFFFFP-1020
 #else
-/* Android, Solaris and DJGPP do not accept 0x for strtod() */
-# if !defined(OF_SOLARIS) || !defined(OF_X86)
+/* Android, Solaris, DJGPP and AmigaOS3 do not accept 0x for strtod() */
+# if (!defined(OF_SOLARIS) || !defined(OF_X86)) && !defined(OF_AMIGAOS3)
 #  define INPUT @"\t-0.123456789 "
 #  define EXPECTED -0.123456789
 # else
-/* Solaris' strtod() has weird rounding on x86, but not on x86_64 */
+/*
+ * Solaris' strtod() has weird rounding on x86, but not on x86_64/
+ * AmigaOS 3 with libnix has weird rounding as well.
+ */
 #  define INPUT @"\t-0.125 "
 #  define EXPECTED -0.125
 # endif
 #endif
 	TEST(@"-[doubleValue]",