diff --git a/macros.gnat.in b/macros.gnat.in
index 5a11dc0..23e2aa3 100644
--- a/macros.gnat.in
+++ b/macros.gnat.in
@@ -39,12 +39,12 @@
 # (Otherwise -gnatwe could turn quite harmless conditions into build failures.)
 # -gnatyN turns off style checks. They are irrelevant to packagers.
 
-%Gnatlink_flags %{__global_ldflags} -g
+%Gnatlink_flags %{?__global_ldflags} -g
 # -g makes Gnatlink refrain from deleting binder files so that they can be
 # included in debuginfo packages.
 
 %Gnatmake_optflags -cargs %{Ada_optflags} -largs %{Gnatlink_flags} -margs %{GNAT_builder_flags}
-%GPRbuild_optflags -cargs:Ada %{Ada_optflags} -cargs:C %{optflags} -cargs:C++ %{optflags} -cargs:Fortran %{optflags} -I%{_fmoddir} -largs %{__global_ldflags} -gargs %{GNAT_builder_flags}
+%GPRbuild_optflags -cargs:Ada %{Ada_optflags} -cargs:C %{optflags} -cargs:C++ %{optflags} -cargs:Fortran %{optflags} -I%{_fmoddir} -largs %{?__global_ldflags} -gargs %{GNAT_builder_flags}
 # Gnatmake_optflags and GPRbuild_optflags contain both the parameters for the
 # builder itself and parameters that the builder shall pass to the tools it
 # invokes. -margs and -gargs must be used after all other mode switches to
@@ -63,7 +63,7 @@
                           CFLAGS="${CFLAGS:-%{optflags}}" \\\
                           CXXFLAGS="${CXXFLAGS:-%{optflags}}" \\\
                           FFLAGS="${FFLAGS:-%{optflags} -I%{_fmoddir}}" \\\
-                          LDFLAGS="${LDFLAGS:-%{__global_ldflags}}" \\\
+                          LDFLAGS="${LDFLAGS:-%{?__global_ldflags}}" \\\
                           GNATLINKFLAGS="${GNATLINKFLAGS:--g}" \\\
                           dirgpr=directories.gpr \\\
                           prefix=%{_prefix} \\\