diff --git a/src/library/base/R/dates.R b/src/library/base/R/dates.R
index d2c4bfebc18..a42f4d5cc75 100644
--- a/src/library/base/R/dates.R
+++ b/src/library/base/R/dates.R
@@ -293,9 +293,9 @@ seq.Date <- function(from, to, by, length.out = NULL, along.with = NULL, ...)
     if(is.na(by)) stop("'by' is NA")
 
     res <- switch(missing_arg,
-        from       = seq.int(to   = unclass(to),   by = by,          length.out = length.out),
-        to         = seq.int(from = unclass(from), by = by,          length.out = length.out),
-        length.out = seq.int(from = unclass(from), to = unclass(to), by = by)
+        from       = seq.int(to   = unclass(as.Date(to)),   by = by,                   length.out = length.out),
+        to         = seq.int(from = unclass(as.Date(from)), by = by,                   length.out = length.out),
+        length.out = seq.int(from = unclass(as.Date(from)), to = unclass(as.Date(to)), by = by)
     )
     .Date(res)
 }
diff --git a/tests/datetime3.R b/tests/datetime3.R
index 883e4ebbd9b..9a200b526fc 100644
--- a/tests/datetime3.R
+++ b/tests/datetime3.R
@@ -786,7 +786,19 @@ identicalPlt <- function(x, y, ...)
 stopifnot(identicalPlt(z1, z), identicalPlt(z2, z))
 ## failed previously, incl in rev 88441
 
-
+## strings in one argument of seq.Date always get coerced
+from_str <- "2025-01-01"; to_str <- "2025-01-07"
+full_seq <- seq(as.Date(from_str), as.Date(to_str))
+stopifnot(exprs = {
+  identical(seq(as.Date(from_str), to_str), full_seq)
+  identical(seq(as.Date(from_str), to_str, by=1L), full_seq)
+  identical(seq(as.Date(from_str), to_str, length.out=7L), full_seq)
+  identical(seq(to=as.Date(to_str), length.out=7L, by=1L), full_seq)
+  identical(seq(from=as.Date(from_str), length.out=7L, by=1L), full_seq)
+  identical(seq(to=as.Date(to_str), from_str), full_seq)
+  identical(seq(to=as.Date(to_str), from_str, by=1L), full_seq)
+  identical(seq(to=as.Date(to_str), from_str, length.out=7L), full_seq)
+})
 
 ## keep at end
 rbind(last =  proc.time() - .pt,