diff --git a/conanfile.txt b/conanfile.txt
index 7436f87..51907ba 100644
--- a/conanfile.txt
+++ b/conanfile.txt
@@ -55,6 +55,7 @@ hdf5*:enable_cxx=False
 hdf5*:hl=False
 hdf5*:threadsafe=False
 hdf5*:parallel=False
+hictk*:with_eigen=False
 highfive*:with_boost=False
 highfive*:with_eigen=False
 highfive*:with_opencv=False
diff --git a/src/hictkr_file.cpp b/src/hictkr_file.cpp
index b7577b7..0fbf136 100644
--- a/src/hictkr_file.cpp
+++ b/src/hictkr_file.cpp
@@ -255,13 +255,16 @@ static Rcpp::NumericMatrix fetch_as_matrix(const Selector &sel) {
     matrix.at(i1, i2) = tp.count;
 
     if (mirror_matrix) {
-      //  Mirror matrix below diagonal
-      if (i2 - i1 < num_rows && i1 < num_cols && i2 < num_rows) {
+      const auto delta = i2 - i1;
+      if (delta >= 0 && delta < num_rows && i1 < num_cols && i2 < num_rows) {
         matrix.at(i2, i1) = tp.count;
-      } else if (i2 - i1 > num_cols && i1 < num_cols && i2 < num_rows) {
+      } else if ((delta < 0 || delta > num_cols) && i1 < num_cols && i2 < num_rows) {
         const auto i3 = static_cast<std::int64_t>(tp.bin2_id - row_offset);
         const auto i4 = static_cast<std::int64_t>(tp.bin1_id - col_offset);
-        matrix.at(i3, i4) = tp.count;
+
+        if (i3 >= 0 && i3 < num_rows && i4 >= 0 && i4 < num_cols) {
+          matrix.at(i3, i4) = tp.count;
+        }
       }
     }
   });
diff --git a/tests/testthat/test-fetch-dense.R b/tests/testthat/test-fetch-dense.R
index c00e303..9e90cda 100644
--- a/tests/testthat/test-fetch-dense.R
+++ b/tests/testthat/test-fetch-dense.R
@@ -19,7 +19,7 @@ for (path in test_files) {
     expect_equal(sum_, 178263235)
   })
 
-  test_that("HiCFile: fetch (dense) cis", {
+  test_that("HiCFile: fetch (dense) symmetric cis", {
     f <- File(path, 100000)
 
     m <- fetch(f, "chr2R:10,000,000-15,000,000", type="dense")
@@ -31,6 +31,35 @@ for (path in test_files) {
     expect_equal(sum_, 6029333)
   })
 
+  test_that("HiCFile: fetch (dense) asymmetric cis", {
+    f <- File(path, 100000)
+
+    m <- fetch(f, "chr2L:0-10,000,000", "chr2L:5,000,000-20,000,000", type="dense")
+
+    shape <- dim(m)
+    sum_ <- sum(m)
+
+    expect_equal(shape, c(100, 150))
+    expect_equal(sum_, 6287451)
+
+
+    m <- fetch(f, "chr2L:0-10,000,000", "chr2L:10,000,000-20,000,000", type="dense")
+
+    shape <- dim(m)
+    sum_ <- sum(m)
+
+    expect_equal(shape, c(100, 100))
+    expect_equal(sum_, 761223)
+
+    m <- fetch(f, "chr2L:0-10,000,000", "chr2L:0-15,000,000", type="dense")
+
+    shape <- dim(m)
+    sum_ <- sum(m)
+
+    expect_equal(shape, c(100, 150))
+    expect_equal(sum_, 12607205)
+  })
+
   test_that("HiCFile: fetch (dense) cis BED queries", {
     f <- File(path, 100000)