diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 9c02141e2c6..c30f67cd2da 100644
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -22726,9 +22726,27 @@ c_parser_omp_requires (c_parser *parser)
 	  enum omp_requires this_req = (enum omp_requires) 0;
 
 	  if (!strcmp (p, "unified_address"))
-	    this_req = OMP_REQUIRES_UNIFIED_ADDRESS;
+	    {
+	      this_req = OMP_REQUIRES_UNIFIED_ADDRESS;
+
+	      if (flag_offload_memory != OFFLOAD_MEMORY_UNIFIED
+		  && flag_offload_memory != OFFLOAD_MEMORY_NONE)
+		error_at (cloc,
+			  "%<unified_address%> is incompatible with the "
+			  "selected %<-foffload-memory%> option");
+	      flag_offload_memory = OFFLOAD_MEMORY_UNIFIED;
+	    }
 	  else if (!strcmp (p, "unified_shared_memory"))
-	    this_req = OMP_REQUIRES_UNIFIED_SHARED_MEMORY;
+	    {
+	      this_req = OMP_REQUIRES_UNIFIED_SHARED_MEMORY;
+
+	      if (flag_offload_memory != OFFLOAD_MEMORY_UNIFIED
+		  && flag_offload_memory != OFFLOAD_MEMORY_NONE)
+		error_at (cloc,
+			  "%<unified_shared_memory%> is incompatible with the "
+			  "selected %<-foffload-memory%> option");
+	      flag_offload_memory = OFFLOAD_MEMORY_UNIFIED;
+	    }
 	  else if (!strcmp (p, "dynamic_allocators"))
 	    this_req = OMP_REQUIRES_DYNAMIC_ALLOCATORS;
 	  else if (!strcmp (p, "reverse_offload"))
diff --git a/gcc/cp/parser.cc b/gcc/cp/parser.cc
index df657a3fb2b..3deafc7c928 100644
--- a/gcc/cp/parser.cc
+++ b/gcc/cp/parser.cc
@@ -46860,9 +46860,27 @@ cp_parser_omp_requires (cp_parser *parser, cp_token *pragma_tok)
 	  enum omp_requires this_req = (enum omp_requires) 0;
 
 	  if (!strcmp (p, "unified_address"))
-	    this_req = OMP_REQUIRES_UNIFIED_ADDRESS;
+	    {
+	      this_req = OMP_REQUIRES_UNIFIED_ADDRESS;
+
+	      if (flag_offload_memory != OFFLOAD_MEMORY_UNIFIED
+		  && flag_offload_memory != OFFLOAD_MEMORY_NONE)
+		error_at (cloc,
+			  "%<unified_address%> is incompatible with the "
+			  "selected %<-foffload-memory%> option");
+	      flag_offload_memory = OFFLOAD_MEMORY_UNIFIED;
+	    }
 	  else if (!strcmp (p, "unified_shared_memory"))
-	    this_req = OMP_REQUIRES_UNIFIED_SHARED_MEMORY;
+	    {
+	      this_req = OMP_REQUIRES_UNIFIED_SHARED_MEMORY;
+
+	      if (flag_offload_memory != OFFLOAD_MEMORY_UNIFIED
+		  && flag_offload_memory != OFFLOAD_MEMORY_NONE)
+		error_at (cloc,
+			  "%<unified_shared_memory%> is incompatible with the "
+			  "selected %<-foffload-memory%> option");
+	      flag_offload_memory = OFFLOAD_MEMORY_UNIFIED;
+	    }
 	  else if (!strcmp (p, "dynamic_allocators"))
 	    this_req = OMP_REQUIRES_DYNAMIC_ALLOCATORS;
 	  else if (!strcmp (p, "reverse_offload"))
diff --git a/gcc/fortran/openmp.cc b/gcc/fortran/openmp.cc
index bd4ff259fe0..91bf8a3c50d 100644
--- a/gcc/fortran/openmp.cc
+++ b/gcc/fortran/openmp.cc
@@ -29,6 +29,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "diagnostic.h"
 #include "gomp-constants.h"
 #include "target-memory.h"  /* For gfc_encode_character.  */
+#include "options.h"
 
 /* Match an end of OpenMP directive.  End of OpenMP directive is optional
    whitespace, followed by '\n' or comment '!'.  */
@@ -5556,6 +5557,12 @@ gfc_match_omp_requires (void)
 	  requires_clause = OMP_REQ_UNIFIED_ADDRESS;
 	  if (requires_clauses & OMP_REQ_UNIFIED_ADDRESS)
 	    goto duplicate_clause;
+
+	  if (flag_offload_memory != OFFLOAD_MEMORY_UNIFIED
+	      && flag_offload_memory != OFFLOAD_MEMORY_NONE)
+	    gfc_error_now ("unified_address at %C is incompatible with "
+			   "the selected -foffload-memory option");
+	  flag_offload_memory = OFFLOAD_MEMORY_UNIFIED;
 	}
       else if (gfc_match (clauses[2]) == MATCH_YES)
 	{
@@ -5563,6 +5570,12 @@ gfc_match_omp_requires (void)
 	  requires_clause = OMP_REQ_UNIFIED_SHARED_MEMORY;
 	  if (requires_clauses & OMP_REQ_UNIFIED_SHARED_MEMORY)
 	    goto duplicate_clause;
+
+	  if (flag_offload_memory != OFFLOAD_MEMORY_UNIFIED
+	      && flag_offload_memory != OFFLOAD_MEMORY_NONE)
+	    gfc_error_now ("unified_shared_memory at %C is incompatible with "
+			   "the selected -foffload-memory option");
+	  flag_offload_memory = OFFLOAD_MEMORY_UNIFIED;
 	}
       else if (gfc_match (clauses[3]) == MATCH_YES)
 	{
diff --git a/gcc/testsuite/c-c++-common/gomp/usm-1.c b/gcc/testsuite/c-c++-common/gomp/usm-1.c
new file mode 100644
index 00000000000..8d2ba62aba3
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/usm-1.c
@@ -0,0 +1,4 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-foffload-memory=pinned" } */
+
+#pragma omp requires unified_shared_memory  /* { dg-error ".unified_shared_memory. is incompatible with the selected .-foffload-memory. option" } */
diff --git a/gcc/testsuite/c-c++-common/gomp/usm-4.c b/gcc/testsuite/c-c++-common/gomp/usm-4.c
new file mode 100644
index 00000000000..84f6f785079
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/gomp/usm-4.c
@@ -0,0 +1,4 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-foffload-memory=pinned" } */
+
+#pragma omp requires unified_address        /* { dg-error ".unified_address. is incompatible with the selected .-foffload-memory. option" } */
diff --git a/gcc/testsuite/gfortran.dg/gomp/usm-1.f90 b/gcc/testsuite/gfortran.dg/gomp/usm-1.f90
new file mode 100644
index 00000000000..340f6bb50a5
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/gomp/usm-1.f90
@@ -0,0 +1,6 @@
+! { dg-do compile }
+! { dg-additional-options "-foffload-memory=pinned" }
+
+!$omp requires unified_shared_memory  ! { dg-error "unified_shared_memory at .* is incompatible with the selected -foffload-memory option" }
+
+end
diff --git a/gcc/testsuite/gfortran.dg/gomp/usm-4.f90 b/gcc/testsuite/gfortran.dg/gomp/usm-4.f90
new file mode 100644
index 00000000000..725b07f2f88
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/gomp/usm-4.f90
@@ -0,0 +1,6 @@
+! { dg-do compile }
+! { dg-additional-options "-foffload-memory=pinned" }
+
+!$omp requires unified_address  ! { dg-error "unified_address at .* is incompatible with the selected -foffload-memory option" }
+
+end