diff --git a/dtool/pptempl/Global.pp b/dtool/pptempl/Global.pp
index 656fb07769..02453d95bf 100644
--- a/dtool/pptempl/Global.pp
+++ b/dtool/pptempl/Global.pp
@@ -555,18 +555,26 @@
 #endif
 
 #define other_trees
+#define other_trees_lib
+#define other_trees_include
 #foreach tree $[NEEDS_TREES]
   #define tree_install $[$[upcase $[tree]]_INSTALL]
   #if $[eq $[tree_install],]
 Warning: Variable $[upcase $[tree]]_INSTALL is not set!
   #else
     #set other_trees $[other_trees] $[tree_install]
+    #set other_trees_lib $[other_trees_lib] $[tree_install]/lib
+    #set other_trees_include $[other_trees_include] $[tree_install]/include
   #endif
 #end tree
 
 #define install_lib_dir $[or $[INSTALL_LIB_DIR],$[install_dir]/lib]
-#define install_bin_dir $[or $[INSTALL_BIN_DIR],$[install_dir]/bin]
+#define other_trees_lib $[or $[INSTALL_LIB_DIR],$[other_trees_lib]]
+
 #define install_headers_dir $[or $[INSTALL_HEADERS_DIR],$[install_dir]/include]
+#define other_trees_include $[or $[INSTALL_HEADERS_DIR],$[other_trees_include]]
+
+#define install_bin_dir $[or $[INSTALL_BIN_DIR],$[install_dir]/bin]
 #define install_data_dir $[or $[INSTALL_DATA_DIR],$[install_dir]/shared]
 #define install_igatedb_dir $[or $[INSTALL_IGATEDB_DIR],$[install_dir]/etc]
 #define install_config_dir $[or $[INSTALL_CONFIG_DIR],$[install_dir]/etc]
diff --git a/dtool/pptempl/Template.gmsvc.pp b/dtool/pptempl/Template.gmsvc.pp
index ac87dd0b43..1eabdf3969 100644
--- a/dtool/pptempl/Template.gmsvc.pp
+++ b/dtool/pptempl/Template.gmsvc.pp
@@ -128,7 +128,7 @@
 // $[target_ipath] is the proper ipath to put on the command line,
 // from the context of a particular target.
 
-#defer target_ipath $[TOPDIR] $[sort $[complete_ipath]] $[other_trees:%=%/include] $[get_ipath]
+#defer target_ipath $[TOPDIR] $[sort $[complete_ipath]] $[other_trees_include] $[get_ipath]
 
 // These are the complete set of extra flags the compiler requires.
 #defer cflags $[get_cflags] $[CFLAGS] $[CFLAGS_OPT$[OPTIMIZE]]
@@ -140,7 +140,7 @@
 
 // $[lpath] is like $[target_ipath]: it's the list of directories we
 // should add to our -L list, from the context of a particular target.
-#defer lpath $[sort $[complete_lpath]] $[other_trees:%=%/lib] $[get_lpath]
+#defer lpath $[sort $[complete_lpath]] $[other_trees_lib] $[get_lpath]
 
 // $[libs] is the set of libraries we will link with.
 #defer libs $[unique $[actual_local_libs:%=%$[dllext]] $[patsubst %:c,,%:m %,%$[dllext],$[OTHER_LIBS]] $[get_libs]]
diff --git a/dtool/pptempl/Template.unix.pp b/dtool/pptempl/Template.unix.pp
index 152776f9f6..f47ee719cb 100644
--- a/dtool/pptempl/Template.unix.pp
+++ b/dtool/pptempl/Template.unix.pp
@@ -103,7 +103,7 @@
 // $[target_ipath] is the proper ipath to put on the command line,
 // from the context of a particular target.
 
-#defer target_ipath $[TOPDIR] $[sort $[complete_ipath]] $[other_trees:%=%/include] $[get_ipath]
+#defer target_ipath $[TOPDIR] $[sort $[complete_ipath]] $[other_trees_include] $[get_ipath]
 
 // These are the complete set of extra flags the compiler requires.
 #defer cflags $[get_cflags] $[CFLAGS] $[CFLAGS_OPT$[OPTIMIZE]] 
@@ -116,7 +116,7 @@
 
 // $[lpath] is like $[target_ipath]: it's the list of directories we
 // should add to our -L list, from the context of a particular target.
-#defer lpath $[sort $[complete_lpath]] $[other_trees:%=%/lib] $[get_lpath]
+#defer lpath $[sort $[complete_lpath]] $[other_trees_lib] $[install_lib_dir] $[get_lpath]
 
 // And $[libs] is the set of libraries we will link with.
 #defer libs $[unique $[actual_local_libs:%=%$[dllext]] $[patsubst %:m,,%:c %,%$[dllext],$[OTHER_LIBS]] $[get_libs]]