diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index e9030900eba..def238f3531 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,7 +1,13 @@
+2007-09-21  Tobias Burnus  <burnus@net-b.de>
+
+	PR fortran/33037
+	* simplify.c (gfc_simplify_transfer): Warn if source size
+	is smaller than result size.
+
 2007-09-20  Asher Langton  <langton2@llnl.gov>
 
 	PR fortran/20441
-        * gfortran.h : Add init_local_* enums and init_flag_* flags to
+	* gfortran.h : Add init_local_* enums and init_flag_* flags to
 	gfc_option_t.
 	* lang.opt: Add -finit-local-zero, -finit-real, -finit-integer,
 	-finit-character, and -finit-logical flags.
diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index 3fa52500344..e581a21603b 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -4059,6 +4059,11 @@ gfc_simplify_transfer (gfc_expr *source, gfc_expr *mold, gfc_expr *size)
       result_size = result_elt_size;
     }
 
+  if (source_size < result_size)
+    gfc_warning("Intrinsic TRANSFER at %L has partly undefined result: "
+		"source size %ld < result size %ld", &source->where,
+		(long) source_size, (long) result_size);
+
   /* Allocate the buffer to store the binary version of the source.  */
   buffer_size = MAX (source_size, result_size);
   buffer = (unsigned char*)alloca (buffer_size);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index dd889ff6952..29b0c26a033 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2007-09-21  Tobias Burnus  <burnus@net-b.de>
+
+	PR fortran/33037
+	* gfortran.dg/transfer_check_1.f90: New.
+
 2007-09-20  Asher Langton  <langton2@llnl.gov>
 
 	PR fortran/20441
diff --git a/gcc/testsuite/gfortran.dg/transfer_check_1.f90 b/gcc/testsuite/gfortran.dg/transfer_check_1.f90
new file mode 100644
index 00000000000..26945267d1d
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/transfer_check_1.f90
@@ -0,0 +1,8 @@
+! { dg-do compile }
+! PR fortran/33037
+!
+print *, transfer('x', 0, 20) ! { dg-warning "has partly undefined result" }
+print *, transfer(1_1, 0) ! { dg-warning "has partly undefined result" }
+print *, transfer([1_2,2_2], 0)
+print *, transfer([1_2,2_2], 0_8) ! { dg-warning "has partly undefined result" }
+end