diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index c73f9bc005..d841b6fa8b 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -1325,11 +1325,16 @@ generate_series_step_numeric(PG_FUNCTION_ARGS)
 
 		/*
 		 * Use fctx to keep state from call to call. Seed current with the
-		 * original start value.
+		 * original start value. We must copy the start_num and stop_num
+		 * values rather than pointing to them, since we may have detoasted
+		 * them in the per-call context.
 		 */
-		init_var_from_num(start_num, &fctx->current);
-		init_var_from_num(stop_num, &fctx->stop);
+		init_var(&fctx->current);
+		init_var(&fctx->stop);
 		init_var(&fctx->step);
+
+		set_var_from_num(start_num, &fctx->current);
+		set_var_from_num(stop_num, &fctx->stop);
 		set_var_from_var(&steploc, &fctx->step);
 
 		funcctx->user_fctx = fctx;
diff --git a/src/test/regress/expected/numeric.out b/src/test/regress/expected/numeric.out
index ee6cb50d5a..9d6814564d 100644
--- a/src/test/regress/expected/numeric.out
+++ b/src/test/regress/expected/numeric.out
@@ -1461,3 +1461,41 @@ select (i / (10::numeric ^ 131071))::numeric(1,0)
        9
 (4 rows)
 
+-- Check usage with variables
+select * from generate_series(1::numeric, 3::numeric) i, generate_series(i,3) j;
+ i | j 
+---+---
+ 1 | 1
+ 1 | 2
+ 1 | 3
+ 2 | 2
+ 2 | 3
+ 3 | 3
+(6 rows)
+
+select * from generate_series(1::numeric, 3::numeric) i, generate_series(1,i) j;
+ i | j 
+---+---
+ 1 | 1
+ 2 | 1
+ 2 | 2
+ 3 | 1
+ 3 | 2
+ 3 | 3
+(6 rows)
+
+select * from generate_series(1::numeric, 3::numeric) i, generate_series(1,5,i) j;
+ i | j 
+---+---
+ 1 | 1
+ 1 | 2
+ 1 | 3
+ 1 | 4
+ 1 | 5
+ 2 | 1
+ 2 | 3
+ 2 | 5
+ 3 | 1
+ 3 | 4
+(10 rows)
+
diff --git a/src/test/regress/sql/numeric.sql b/src/test/regress/sql/numeric.sql
index a7e92ac3cc..1633e4c375 100644
--- a/src/test/regress/sql/numeric.sql
+++ b/src/test/regress/sql/numeric.sql
@@ -854,3 +854,7 @@ select (i / (10::numeric ^ 131071))::numeric(1,0)
 	from generate_series(6 * (10::numeric ^ 131071),
 			     9 * (10::numeric ^ 131071),
 			     10::numeric ^ 131071) as a(i);
+-- Check usage with variables
+select * from generate_series(1::numeric, 3::numeric) i, generate_series(i,3) j;
+select * from generate_series(1::numeric, 3::numeric) i, generate_series(1,i) j;
+select * from generate_series(1::numeric, 3::numeric) i, generate_series(1,5,i) j;