diff --git a/tests/checkasm/hevc_deblock.c b/tests/checkasm/hevc_deblock.c
index 66fc8d5646..3f970a470a 100644
--- a/tests/checkasm/hevc_deblock.c
+++ b/tests/checkasm/hevc_deblock.c
@@ -29,8 +29,8 @@
 static const uint32_t pixel_mask[3] = { 0xffffffff, 0x03ff03ff, 0x0fff0fff };
 
 #define SIZEOF_PIXEL ((bit_depth + 7) / 8)
-#define BUF_STRIDE (8 * 2)
-#define BUF_LINES (8)
+#define BUF_STRIDE (16 * 2)
+#define BUF_LINES (16)
 #define BUF_OFFSET (BUF_STRIDE * BUF_LINES)
 #define BUF_SIZE (BUF_STRIDE * BUF_LINES + BUF_OFFSET * 2)
 
@@ -88,14 +88,116 @@ static void check_deblock_chroma(HEVCDSPContext *h, int bit_depth)
     }
 }
 
+// line zero
+#define P3 buf[-4 * xstride]
+#define P2 buf[-3 * xstride]
+#define P1 buf[-2 * xstride]
+#define P0 buf[-1 * xstride]
+#define Q0 buf[0 * xstride]
+#define Q1 buf[1 * xstride]
+#define Q2 buf[2 * xstride]
+#define Q3 buf[3 * xstride]
+
+// line three. used only for deblocking decision
+#define TP3 buf[-4 * xstride + 3 * ystride]
+#define TP2 buf[-3 * xstride + 3 * ystride]
+#define TP1 buf[-2 * xstride + 3 * ystride]
+#define TP0 buf[-1 * xstride + 3 * ystride]
+#define TQ0 buf[0  * xstride + 3 * ystride]
+#define TQ1 buf[1  * xstride + 3 * ystride]
+#define TQ2 buf[2  * xstride + 3 * ystride]
+#define TQ3 buf[3  * xstride + 3 * ystride]
+
+static void randomize_luma_buffers(int type, uint8_t *buf, ptrdiff_t xstride, ptrdiff_t ystride)
+{
+    int i;
+    buf += BUF_OFFSET;
+    switch (type) {
+    case 0: // strong
+        for (i = 0; i < 16; i++) {
+            P3 = P2 = P1 = P0 = 64;
+            Q0 = Q1 = Q2 = Q3 = 80;
+            buf += ystride;
+        }
+        break;
+    case 1: // weak
+        for (i = 0; i < 16; i++) {
+            P3 = P2 = 60; P1 = P0 = 64;
+            Q0 = Q1 = 74; Q2 = Q3 = 80;
+            buf += ystride;
+        }
+        break;
+    case 2: // none
+        for (i = 0; i < 16; i++) {
+            for (int j = -8; j < 8; j++) {
+                buf[j * xstride + i * ystride] = rnd();
+            }
+        }
+        break;
+    }
+}
+
+static void check_deblock_luma(HEVCDSPContext *h, int bit_depth)
+{
+    const char *type;
+    const char *types[3] = { "strong", "normal", "skip" };
+    int beta;
+    int32_t tc[2] = { 0, 0 };
+    // no_p, no_q can only be { 0,0 } for the simpler assembly (non *_c
+    // variant) functions, see deblocking_filter_CTB() in hevc_filter.c
+    uint8_t no_p[2] = { 0, 0 };
+    uint8_t no_q[2] = { 0, 0 };
+    LOCAL_ALIGNED_32(uint8_t, buf0, [BUF_SIZE]);
+    LOCAL_ALIGNED_32(uint8_t, buf1, [BUF_SIZE]);
+
+    declare_func(void, uint8_t *pix, ptrdiff_t stride, int beta, int32_t *tc, uint8_t *no_p, uint8_t *no_q);
+
+    for (int j = 0; j < 3; j++) {
+        beta = (j == 3) ? 0 : 32; // beta easy way to turn off filtering
+        type = types[j];
+
+        // see betatable[] in hevc_filter.c
+        tc[0] = (rnd() & 63) + (rnd() & 1);
+        tc[1] = (rnd() & 63) + (rnd() & 1);
+
+        if (check_func(h->hevc_h_loop_filter_luma, "hevc_h_loop_filter_luma%d_%s", bit_depth, type)) {
+            for (int i = 0; i < 4; i++) {
+                randomize_luma_buffers(j, buf0, 16, 1);
+                memcpy(buf1, buf0, BUF_SIZE);
+
+                call_ref(buf0 + BUF_OFFSET, 16, beta, tc, no_p, no_q);
+                call_new(buf1 + BUF_OFFSET, 16, beta, tc, no_p, no_q);
+                if (memcmp(buf0, buf1, BUF_SIZE))
+                    fail();
+            }
+            bench_new(buf1 + BUF_OFFSET, 16, beta, tc, no_p, no_q);
+        }
+
+        if (check_func(h->hevc_v_loop_filter_luma, "hevc_v_loop_filter_luma%d_%s", bit_depth, type)) {
+            for (int i = 0; i < 4; i++) {
+                randomize_luma_buffers(j, buf0, 1, 16);
+                memcpy(buf1, buf0, BUF_SIZE);
+
+                call_ref(buf0 + BUF_OFFSET, 16, beta, tc, no_p, no_q);
+                call_new(buf1 + BUF_OFFSET, 16, beta, tc, no_p, no_q);
+                if (memcmp(buf0, buf1, BUF_SIZE))
+                    fail();
+            }
+            bench_new(buf1 + BUF_OFFSET, 16, beta, tc, no_p, no_q);
+        }
+    }
+}
+
 void checkasm_check_hevc_deblock(void)
 {
+    HEVCDSPContext h;
     int bit_depth;
-
     for (bit_depth = 8; bit_depth <= 12; bit_depth += 2) {
-        HEVCDSPContext h;
         ff_hevc_dsp_init(&h, bit_depth);
         check_deblock_chroma(&h, bit_depth);
     }
     report("chroma");
+    ff_hevc_dsp_init(&h, 8);
+    check_deblock_luma(&h, 8);
+    report("luma");
 }
