diff --git a/ggml/src/ggml-quants.c b/ggml/src/ggml-quants.c
index 20a9831b3..b8d0d8def 100644
--- a/ggml/src/ggml-quants.c
+++ b/ggml/src/ggml-quants.c
@@ -1916,7 +1916,7 @@ static float make_qkx1_quants(int n, int nmax, const float * restrict x, uint8_t
         if (x[i] < min) min = x[i];
         if (x[i] > max) max = x[i];
     }
-    if (max == min) {
+    if (max - min < 1e-10f) {
         for (int i = 0; i < n; ++i) L[i] = 0;
         *the_min = 0;
         return 0.f;
@@ -1971,7 +1971,7 @@ static float make_qkx2_quants(int n, int nmax, const float * restrict x, const f
         sum_x += w * x[i];
     }
     if (min > 0) min = 0;
-    if (max == min) {
+    if (max - min < 1e-10f) {
         for (int i = 0; i < n; ++i) L[i] = 0;
         *the_min = -min;
         return 0.f;
@@ -2218,7 +2218,7 @@ static float make_qkx3_quants(int n, int nmax, const float * restrict x, const f
     if (min > 0) {
         min = 0;
     }
-    if (max <= min) {
+    if (max - min < 1e-10f) {
         memset(L, 0, n);
         *the_min = -min;
         return 0.f;
@@ -2340,7 +2340,7 @@ static float make_qp_quants(int n, int nmax, const float * restrict x, uint8_t *
     for (int i = 0; i < n; ++i) {
         max = MAX(max, x[i]);
     }
-    if (!max) { // all zero
+    if (max < 1e-16f) { // all zero
         for (int i = 0; i < n; ++i) { L[i] = 0; }
         return 0.f;
     }
@@ -2733,6 +2733,10 @@ void quantize_row_q4_K_ref(const float * restrict x, block_q4_K * restrict y, in
             float av_x = sqrtf(sum_x2/32);
             for (int l = 0; l < 32; ++l) weights[l] = av_x + fabsf(x[32*j + l]);
             scales[j] = make_qkx2_quants(32, 15, x + 32*j, weights, L + 32*j, &mins[j], Laux, -1.f, 0.1f, 20, false);
+            if (isnan(scales[j])) {
+                printf("Oops: NaN scale\n");
+                GGML_ABORT("Fatal error");
+            }
             float scale = scales[j];
             if (scale > max_scale) {
                 max_scale = scale;
@@ -2846,10 +2850,18 @@ static void quantize_row_q4_K_impl(const float * restrict x, block_q4_K * restri
             for (int l = 0; l < 32; ++l) sumw += weights[l];
             sw[j] = sumw;
             scales[j] = make_qkx3_quants(32, 15, x + 32*j, weights, L + 32*j, &mins[j], Laux, -0.9f, 0.05f, 36, false);
+            if (isnan(scales[j])) {
+                printf("%s: got NaN scale\n", __func__);
+                GGML_ABORT("Fatal error");
+            }
         }
 
         float d_block = make_qp_quants(QK_K/32, 63, scales, Ls, sw);
         float m_block = make_qp_quants(QK_K/32, 63, mins,   Lm, sw);
+        if (isnan(d_block) || isnan(m_block)) {
+            printf("%s: d_block = %g, m_block = %g\n", __func__, (double)d_block, (double)m_block);
+            GGML_ABORT("Fatal error");
+        }
         for (int j = 0; j < QK_K/32; ++j) {
             uint8_t ls = Ls[j];
             uint8_t lm = Lm[j];
diff --git a/ggml/src/iqk/iqk_quantize.cpp b/ggml/src/iqk/iqk_quantize.cpp
index 038cb4fe9..66cfed830 100644
--- a/ggml/src/iqk/iqk_quantize.cpp
+++ b/ggml/src/iqk/iqk_quantize.cpp
@@ -1053,9 +1053,16 @@ void quantize_row_iq2_k_impl(const float * x, void * vy, int n_per_row, const fl
                 for (int j = 0; j < kBlockSize; ++j) weight[j] = 0.25f*sigma2 + xb[j]*xb[j];
             }
             sw[ib] = 0;
+            float amax = 0;
             for (int j = 0; j < kBlockSize; ++j) {
                 sw[ib] += weight[j];
                 pairs[j] = {xb[j], j};
+                float ax = std::abs(xb[j]);
+                amax = std::max(amax, ax);
+            }
+            if (amax < 1e-16f) {
+                scales[ib] = 0;
+                continue;
             }
             std::sort(pairs.begin(), pairs.end());
             sumx[0] = sumw[0] = 0;
@@ -1269,9 +1276,16 @@ void quantize_row_iq2_ks_impl(const float * x, void * vy, int n_per_row, const f
                 for (int j = 0; j < kBlockSize; ++j) weight[j] = 0.25f*sigma2 + xb[j]*xb[j];
             }
             sw[ib] = 0;
+            float amax = 0;
             for (int j = 0; j < kBlockSize; ++j) {
                 sw[ib] += weight[j];
                 pairs[j] = {xb[j], j};
+                float ax = std::abs(xb[j]);
+                amax = std::max(amax, ax);
+            }
+            if (amax < 1e-16f) {
+                scales[ib] = 0;
+                continue;
             }
             //float amax = 0, max = 0;
             //for (int j = 0; j < kBlockSize; ++j) {
@@ -1678,7 +1692,7 @@ void quantize_row_iq2_kl_impl(const float * x, void * vy, int n_per_row, const f
                     amax = ax; max = xb[j];
                 }
             }
-            if (!amax) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }
@@ -1929,7 +1943,7 @@ static void quantize_row_iq3_k_impl(const float * x, void * vy, int n_per_row, c
                     amax = ax; max = xb[j];
                 }
             }
-            if (amax < 1e-9f) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }
@@ -2216,7 +2230,7 @@ static void quantize_row_iq3_ks_impl(const int super_block_size, const int block
                     amax = ax; max = xb[j];
                 }
             }
-            if (amax < 1e-9f) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }
@@ -2544,7 +2558,7 @@ static void quantize_row_iq4_k_impl_bs16(const int super_block_size, const int b
                 amax = ax; max = xb[j];
             }
         }
-        if (!amax) {
+        if (amax < 1e-16f) {
             scales[ib] = 0;
             continue;
         }
@@ -2862,7 +2876,7 @@ void quantize_row_iq5_k_impl(const float * x, void * vy, int n_per_row, const fl
                     amax = ax; max = xb[j];
                 }
             }
-            if (!amax) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }
@@ -3216,7 +3230,7 @@ void quantize_row_iq6_k_impl(const float * x, void * vy, int n_per_row, const fl
                     amax = ax; max = xb[j];
                 }
             }
-            if (!amax) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }
@@ -3918,7 +3932,7 @@ static void quantize_row_iq4_k_impl_bs128(const int super_block_size, const int
                     amax = ax; max = xb[j];
                 }
             }
-            if (!amax) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }
@@ -4167,7 +4181,7 @@ static void quantize_row_iq5_ks_impl(const int super_block_size, const int block
                     amax = ax; max = xb[j];
                 }
             }
-            if (amax < 1e-15f) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }
@@ -4470,7 +4484,7 @@ static void quantize_row_iq4_kss_impl(int n_per_row, const float * x, char * cy,
                     amax = ax; max = xb[j];
                 }
             }
-            if (!amax) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }
@@ -8733,6 +8747,11 @@ void quantize_row_iq1_kt_impl(const float * x, void * vy, int n_per_row, const f
                 float ax = std::abs(xb[j]);
                 amax = std::max(amax, ax);
             }
+            if (amax < 1e-16f) {
+                scales[ib] = 0.0f;
+                for (int ig = 0; ig < Q::kNg; ++ig) all_idx[(ibl*Q::kSuperBlockSize + ib*Q::kBlockSize)/Q::kGroupSize + ig] = 0;
+                continue;
+            }
             float scale_0 = std::max(90.f, 124.f*amax/amax_row);
             quantizer.find_best_match( amax/scale_0, xb, weight, best_idx);
             auto [dp, score_p] = quantizer.find_best_scale(xb, weight, best_idx);
@@ -8998,6 +9017,11 @@ void quantize_row_iq2_kt_impl(const float * x, void * vy, int n_per_row, const f
                 float ax = std::abs(xb[j]);
                 amax = std::max(amax, ax);
             }
+            if (amax < 1e-16f) {
+                scales[ib] = 0.0f;
+                for (int ig = 0; ig < Q::kNg; ++ig) all_idx[(ibl*Q::kSuperBlockSize + ib*Q::kBlockSize)/Q::kGroupSize + ig] = 0;
+                continue;
+            }
             float scale_0 = std::max(90.f, 124.f*amax/amax_row);
             quantizer.find_best_match( amax/scale_0, xb, weight, best_idx);
             auto [dp, score_p] = quantizer.find_best_scale(xb, weight, best_idx);
@@ -9289,8 +9313,10 @@ void quantize_row_iq3_kt_impl(const float * x, void * vy, int n_per_row, const f
                 xaux[j] = ax;
                 amax = std::max(amax, ax);
             }
-            scales[ib] = 0;
-            if (!amax) continue;
+            if (amax < 1e-16f) {
+                scales[ib] = 0.0f;
+                continue;
+            }
 
             //quantizer.find_best_match(amax/96.f, xaux, weight, best_idx+Q::kNg);
             //scales[ib] = quantizer.find_best_scale(xaux, weight, best_idx+Q::kNg).first;
@@ -9577,7 +9603,7 @@ void quantize_row_iq4_kt_impl(const float * x, void * vy, int n_per_row, const f
                 float ax = std::abs(xaux[j]);
                 amax = std::max(amax, ax);
             }
-            if (!amax) {
+            if (amax < 1e-16f) {
                 scales[ib] = 0;
                 continue;
             }