diff --git a/0ad.spec b/0ad.spec
index 618a43d..af36b88 100644
--- a/0ad.spec
+++ b/0ad.spec
@@ -41,7 +41,7 @@ Group:		Amusements/Games
 Summary:	Cross-Platform RTS Game of Ancient Warfare
 Url:		http://play0ad.com
 
-%if %{without nvtt}
+%if ! %{with nvtt}
 # wget http://releases.wildfiregames.com/%%{name}-%%{version}-alpha-unix-build.tar.xz
 # tar Jxf %%{name}-%%{version}-alpha-unix-build.tar.xz
 # rm -fr %%{name}-%%{version}-alpha/libraries/nvtt
@@ -121,8 +121,8 @@ hobbyist game developers, since 2001.
 #-----------------------------------------------------------------------
 %prep
 %setup -q -n %{name}-%{version}-alpha
-%patch0 -p0
-%if %{without debug}
+%patch0 -p1
+%if ! %{with debug}
 # disable debug build, and "int 0x3" to trap to debugger (x86 only)
 %patch1 -p0
 %endif
@@ -147,7 +147,7 @@ build/workspaces/update-workspaces.sh	\
 %if %{with system_nvtt}
     --with-system-nvtt			\
 %endif
-%if %{without nvtt}
+%if ! %{with nvtt}
     --without-nvtt			\
 %endif
     %{?_smp_mflags}
@@ -173,7 +173,7 @@ for name in AtlasUI%{dbg} Collada%{dbg}; do
     install -p -m 755 binaries/system/lib${name}.so %{buildroot}%{_libdir}/%{name}/lib${name}.so
 done
 
-%if %{with nvtt} && %{without system_nvtt}
+%if %{with nvtt} && ! %{with system_nvtt}
 for name in nvcore nvimage nvmath nvtt; do
     install -p -m 755 binaries/system/lib${name}.so %{buildroot}%{_libdir}/%{name}/lib${name}.so
 done