diff --git a/tools/g-ir-tool-template.in b/tools/g-ir-tool-template.in
index 75c35a7..499ed01 100644
--- a/tools/g-ir-tool-template.in
+++ b/tools/g-ir-tool-template.in
@@ -46,7 +46,7 @@ if debug:
 filedir = os.path.dirname(__file__)
 
 # Try using relative paths first so that the installation prefix is relocatable
-datadir = os.path.abspath(os.path.join(filedir, '..', 'share'))
+datadir = os.path.abspath(os.path.join(filedir, '..', '..', 'share'))
 # Fallback to hard-coded paths if the relocatable paths are wrong
 if not os.path.isdir(os.path.join(datadir, 'gir-1.0')):
     datadir = "@datarootdir@"
@@ -55,7 +55,7 @@ builtins.__dict__['DATADIR'] = datadir
 
 # Respect gir_dir_prefix
 girdir = ''
-girdir = os.path.abspath(os.path.join(filedir, '..', '@gir_dir_prefix@'))
+girdir = datadir
 builtins.__dict__['GIRDIR'] = [girdir]
 
 # Again, relative paths first so that the installation prefix is relocatable