diff --git a/R/bmerge.R b/R/bmerge.R
index 7b8d84021..21c7345da 100644
--- a/R/bmerge.R
+++ b/R/bmerge.R
@@ -104,7 +104,7 @@ bmerge = function(i, x, icols, xcols, roll, rollends, nomatch, mult, ops, verbos
       } else stopf("Incompatible join types: %s is type integer64 but %s is type double and contains fractions", nm[2L], nm[1L])
     } else {
       # just integer and double left
-      ic_idx = which(ic == icols)
+      ic_idx = which(ic == icols) # check if on is joined on multiple conditions
       if (i_merge_type=="double") {
         coerce_x = FALSE
         if (!isReallyReal(i[[ic]])) {
@@ -113,7 +113,7 @@ bmerge = function(i, x, icols, xcols, roll, rollends, nomatch, mult, ops, verbos
           # we've always coerced to int and returned int, for convenience.
           if (length(ic_idx)>1L) {
             xc_idx = xcols[ic_idx]
-            for (xb in xcols[which(vapply_1c(x[0L, xc_idx, with=FALSE], getClass) == "double")]) {
+            for (xb in xc_idx[which(vapply_1c(x[0L, xc_idx, with=FALSE], getClass) == "double")]) {
               if (isReallyReal(x[[xb]])) {
                 coerce_x = FALSE
                 break
@@ -127,7 +127,7 @@ bmerge = function(i, x, icols, xcols, roll, rollends, nomatch, mult, ops, verbos
             set(callersi, j=ic, value=val)       # change the shallow copy of i up in [.data.table to reflect in the result, too.
             if (length(ic_idx)>1L) {
               xc_idx = xcols[ic_idx]
-              for (xb in xcols[which(vapply_1c(x[0L, xc_idx, with=FALSE], getClass) == "double")]) {
+              for (xb in xc_idx[which(vapply_1c(x[0L, xc_idx, with=FALSE], getClass) == "double")]) {
                 if (verbose) catf("Coercing double column %s (which contains no fractions) to type integer to match type of %s.\n", paste0("x.", names(x)[xb]), xname)
                 set(x, j=xb, value=cast_with_atts(x[[xb]], as.integer))
               }
@@ -144,7 +144,7 @@ bmerge = function(i, x, icols, xcols, roll, rollends, nomatch, mult, ops, verbos
         set(i, j=ic, value=val)
         if (length(ic_idx)>1L) {
           xc_idx = xcols[ic_idx]
-          for (xb in xcols[which(vapply_1c(x[0L, xc_idx, with=FALSE], getClass) == "integer")]) {
+          for (xb in xc_idx[which(vapply_1c(x[0L, xc_idx, with=FALSE], getClass) == "integer")]) {
             if (verbose) catf("Coercing integer column %s to type double for join to match type of %s.\n", paste0("x.", names(x)[xb]), xname)
             set(x, j=xb, value=cast_with_atts(x[[xb]], as.double))
           }
diff --git a/inst/tests/tests.Rraw b/inst/tests/tests.Rraw
index 6dbfa66a5..9f9aa2aa0 100644
--- a/inst/tests/tests.Rraw
+++ b/inst/tests/tests.Rraw
@@ -12226,11 +12226,10 @@ DT1 = data.table(RANDOM_STRING = rand_strings(n),
                  DATE = sample(seq(as.Date('2016-01-01'), as.Date('2016-12-31'), by="day"), n, replace=TRUE))
 DT2 = data.table(RANDOM_STRING = rand_strings(n),
                  START_DATE = sample(seq(as.Date('2015-01-01'), as.Date('2017-12-31'), by="day"), n, replace=TRUE))
-as.intDate = function(x) .Date(as.integer(as.Date(x)))
 DT2[, EXPIRY_DATE := START_DATE + floor(runif(1000, 200,300))]
-DT1[, DT1_ID := .I][, DATE := as.intDate(DATE)]
+DT1[, DT1_ID := .I][, DATE := as.Date(DATE)]
 cols = c("START_DATE", "EXPIRY_DATE")
-DT2[, DT2_ID := .I][, (cols) := lapply(.SD, as.intDate), .SDcols=cols]
+DT2[, DT2_ID := .I][, (cols) := lapply(.SD, as.Date), .SDcols=cols]
 ans1 = DT2[DT1, on=.(RANDOM_STRING, START_DATE <= DATE, EXPIRY_DATE >= DATE), .N, by=.EACHI ]$N > 0L
 tmp  = DT1[DT2, on=.(RANDOM_STRING, DATE >= START_DATE, DATE <= EXPIRY_DATE), which=TRUE, nomatch=0L]
 ans2 = DT1[, DT1_ID %in% tmp]