diff --git a/config.scm b/config.scm
index decc94d1..f93ebd5e 100644
--- a/config.scm
+++ b/config.scm
@@ -52,12 +52,15 @@
          ((import)
           (let ((mod2 (load-module (cadr x))))
             (%env-copy! env (module-env mod2) (module-exports mod2))))
-         ((include)
+         ((include include-shared)
           (for-each
            (lambda (f)
-             (cond
-              ((find-module-file name f) => (lambda (x) (load x env)))
-              (else (error "couldn't find include" f))))
+             (let ((f (if (eq? (car x) 'include)
+                          f
+                          (string-append f *shared-object-extension*))))
+               (cond
+                ((find-module-file name f) => (lambda (x) (load x env)))
+                (else (error "couldn't find include" f)))))
            (cdr x)))
          ((body)
           (for-each (lambda (expr) (eval expr env)) (cdr x)))))
@@ -98,6 +101,7 @@
 (define-config-primitive import)
 (define-config-primitive export)
 (define-config-primitive include)
+(define-config-primitive include-shared)
 (define-config-primitive body)
 
 (let ((exports
diff --git a/eval.c b/eval.c
index 1cff2b2f..21c23513 100644
--- a/eval.c
+++ b/eval.c
@@ -2356,6 +2356,8 @@ static sexp sexp_make_standard_env (sexp ctx, sexp version) {
   sexp_env_define(ctx, e, sexp_global(ctx, SEXP_G_INTERACTION_ENV_SYMBOL), e);
   sexp_env_define(ctx, e, sexp_intern(ctx, "*module-directory*"),
                   sexp_c_string(ctx, sexp_module_dir, -1));
+  sexp_env_define(ctx, e, sexp_intern(ctx, "*shared-object-extension*"),
+                  sexp_c_string(ctx, sexp_so_extension, -1));
   /* add default exception handler */
   err_cell = sexp_env_cell(e, sexp_global(ctx, SEXP_G_CUR_ERR_SYMBOL));
   perr_cell = sexp_env_cell(e, sexp_intern(ctx, "print-exception"));
diff --git a/lib/srfi/69.module b/lib/srfi/69.module
index 8c64a4e9..5d2f040b 100644
--- a/lib/srfi/69.module
+++ b/lib/srfi/69.module
@@ -12,7 +12,6 @@
    hash string-hash string-ci-hash hash-by-identity)
   (import (scheme))
   (import (srfi 9))
-  (include "srfi/69/type.scm"
-           "srfi/69/hash.so"
-           "srfi/69/interface.scm"))
+  (include-shared "srfi/69/hash")
+  (include "srfi/69/type.scm" "srfi/69/interface.scm"))
 
diff --git a/lib/srfi/98.module b/lib/srfi/98.module
index 55dfb45b..b3e58525 100644
--- a/lib/srfi/98.module
+++ b/lib/srfi/98.module
@@ -1,5 +1,5 @@
 
 (define-module (srfi 98)
   (export get-environment-variable get-environment-variables)
-  (include "srfi/98/env.so"))
+  (include-shared "srfi/98/env"))